The invention pertains to the field of forming elongated glass fiber elements impregnated with a hardenable dialectric resin wherein such elements may be used for radio antennae.
The popularity of the citizens band radio has developed a need for effective antennas whereby the antenna conductor may be maintained in an extended condition, usually vertical, so as to most effectively transmit and receive radio frequency signals. The shorter antennas available merely consist of a conductor of sufficient strength to support itself, however, radio frequencies are often adversely affected by utilizing antenna conductors of a diameter larger than necessary to most effectively handle the signal, but an increased antenna diameter is necessary for self standing and strength requirements.
If the antenna conductor is supported by a rigid member it is possible to extend the antenna conductor length to a height considerably greater than if the conductor itself is self supporting. For this purpose antennas have been mounted upon wood or fiber glass extensions, but such extensions become troublesome from a maintenance standpoint as they are often damaged by low clearance objects, such as branches, and vibration and movement imposed thereon often causes fracturing due to fatigue.
The encasing of the antenna conductor within a semi-rigid jacket, such as hardened resin, permits a relatively long antenna to be self standing, flexible enough to withstand vibration and impact with stationary objects, and such antennas are commonly referred to as "whip" antennas. This type of antenna has enjoyed popularity in many installations on vehicles, however, manufacturing costs are relatively expensive and it is difficult to provide a high-grade finish upon the resin which is acceptable from an appearance standpoint. Further, manufacturing techniques employed in the past have resulted in weak spots occuring in the resin jacket increasing likelihood of stress points developing. Such resin coated antennas must often be sized and finished by expensive secondary operations, and manufacturing techniques require that the price of such antennas be higher than affordable by many citizen band radio owners.